A critical dilemma facing chemical and biological toxin detection is that in many instances only a very limited number of molecules may be available for analysis. Moreover, current methods are ill equipped or incapable of reliably concentrating and processing very small quantities of a target agent. Most rely on aerosol capture into a substrate fluid. Because of dilution and successive discarding of fluid, many molecules must be collected in order to provide an effectively concentrated solution with which to perform chemical analysis. Unfortunately, this can delay analysis for many minutes and/or lead to unreliable results. In addition, the number of molecules of interest may be limited and amplification of these molecules may not be an option. Therefore, the available sample must be neither wasted nor diluted and it must be processed in a manner capable of screening it from other species.
A method and apparatus is herein disclosed that combines the utility of several known technologies to address this problem. In particular, picoliter chambers comprising phospholipid vesicles about 1-20 microns in diameter, are used to manipulate and chemically process trace quantities of samples. These chambers are formed from synthetic lipids by well known methods, such as are described by Fischer, et al., (Biochimica et Biophysica Acta, 2000, v.1467, pp. 177-188); and by Bucher, et al. (Langmuir, 1998,v.14, pp. 2712-2721); or are created from preexisting cells (e.g. ghost red blood cells or “RBCs”). Due to their small size and composition, the vesicles serve as ideal biomimetic (i.e., human-made processes/devices/systems that imitate nature) nano-environments and provide for rapid, surface-functionalized chemical kinetics. Additionally, the vesicles are manipulated and moved through a fluidic network to specific locations where various reagents, analytes, proteins, or viruses are introduced into individual vesicles via electroporation, a well known technique in which the bilayer vesicle membrane is rendered temporarily porous under an applied electric field (see T. Y. Tsong, et al., Biophysical Journal, 1991, v.60, pp. 297-306). Finally, successive electroporation steps allow multiple-part reactions to take place within the confines of a vesicle, and allow the localized release of products for analysis.